U.S. patent number 4,676,690 [Application Number 06/457,732] was granted by the patent office on 1987-06-30 for material spreader system.
This patent grant is currently assigned to Allen Engineering Corporation. Invention is credited to J. Dewayne Allen.
United States Patent |
4,676,690 |
Allen |
* June 30, 1987 |
Material spreader system
Abstract
A material spreader system includes an elevated bridge for
spanning a section of plastic concrete. A spreader including a
hopper having an elongated rectangular slot is translated back and
forth across the bridge to dispense a widthwise stream of topping
material onto the underlying surface. Vibration generating elements
are coupled at spaced apart intervals to the spreader hopper to
provide for a uniform flow of topping material to the slot. A flow
control device spans the length of the slot to dispense a
continuous stream of topping material from the slot. A rotating
metering device meters the flow of topping material through the
slot. A motor translates the spreader back and forth across the
bridge and rotates the rotating metering device as the spreader
moves such that sequential translations of the spreader across the
bridge followed by sequential translations of the bridge along the
length of the plastic surface covers the entire surface with a
uniform blanket of topping material.
Inventors: |
Allen; J. Dewayne (Paragould,
AR) |
Assignee: |
Allen Engineering Corporation
(Paragould, AR)
|
[*] Notice: |
The portion of the term of this patent
subsequent to September 14, 1999 has been disclaimed. |
Family
ID: |
26865730 |
Appl.
No.: |
06/457,732 |
Filed: |
January 13, 1983 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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311674 |
Oct 15, 1981 |
4540312 |
|
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170126 |
Jul 18, 1980 |
4349294 |
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101545 |
Dec 10, 1979 |
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Current U.S.
Class: |
404/110; 222/196;
222/556; 222/626; 404/101; 404/108 |
Current CPC
Class: |
E01C
19/2035 (20130101); E01C 7/35 (20130101) |
Current International
Class: |
E01C
7/00 (20060101); E01C 19/20 (20060101); E01C
19/00 (20060101); E01C 7/35 (20060101); E01C
019/18 () |
Field of
Search: |
;404/101,105,106,119,108,110,113
;222/608-614,623-626,173,195,196,627,556,557
;118/108,207,305,323 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
1968 Concrete Construction Magazine article relating to a material
spreader system..
|
Primary Examiner: Rolla; Joseph J.
Assistant Examiner: Shaver; Kevin P.
Attorney, Agent or Firm: Cahill, Sutton & Thomas
Claims
I claim:
1. Apparatus for spreading a uniform blanket of topping material
onto a surface of plastic material having a length and width, said
apparatus comprising:
a. a spreader including a hopper for storing a supply of loose
topping material and for dispensing a stream of topping material
from an elongated slot in said hopper as said spreader is
translated back and forth along a path;
b. bridge means supported above and spanning the width of the
plastic surface without contacting the plastic surface and
translatable along the length of the plastic surface for providing
an elevated path to translate said spreader across a widthwise
segment of the plastic surface and for maintaining said spreader
vertically spaced above and separated from the plastic surface,
said bridge means including guide means for confining said spreader
to a fixed path with respect to said bridge means as said spreader
is translated back and forth across said bridge means;
c. meand coupled to said spreader and extending along the entire
length of said elongated slot for metering the discharge of topping
material from said hopper at a rate proportional to the translation
velocity of said spreader across said bridge means and independent
of the vertical spacing between said slot and the plastic surface,
said metering means including a gate displaceable between open and
closed positions and gate actuator means coupled to said gate for
displacing said gate between the open and closed positions;
d. means for agitating the topping material within said hopper and
in proximity to said elongated slot;
e. means coupled to said spreader for vibrating said hopper to
maintain a uniform flow of topping material through said elongated
slot as said spreader is translated back and forth across said
bridge means;
f. drive means coupled to said spreader for translating said
spreader back and forth across said bridge means; and
g. control means coupled to said drive means for controlling the
back and forth translation of said spreader along said bridge means
and coupled to said vibrating means and to said gate actuator means
for energizing said vibration means and displacing said gate into
the open position when said drive means is energized;
whereby sequential translations of said spreader across said bridge
means followed by sequential translations of said bridge means
along the length of the plastic surface covers the entire surface
with a uniform blanket of topping material.
2. Apparatus for spreading a uniform blanket of topping material
onto a surface of a plastic material having a length and a width,
said apparatus comprising:
a. a spreader having a hopper for storing a supply of loose topping
material and for dispensing a stream of topping material from an
elongated slot in said hopper as said spreader is translated back
and forth along a path, said spreader including a roller assembly
having first and second spaced apart trucks, said hopper including
first and second opposing, inclined walls having parallel oriented,
adjacent lower surfaces which converge together to form said
elongated slot;
b. bridge means spanning the width of the plastic surface without
contacting the plastic surface and translatable along the length of
the plastic surface for providing an elevated path to support the
roller assembly of said spreader and to permit translation of said
spreader across a widthwise segment of the plastic surface while
maintaining said spreader vertically spaced above and separated
from the plastic surface, said bridge means including guide means
engaging said roller assembly to confine said spreader to a fixed
path with respect to said bridge means as said spreader is
translated back and forth across said bridge means;
c. means coupled to said spreader and engaging said elongated slot
for metering the discharge of topping material from said hopper at
a rate proportional to the translation velocity of said spreader
across said bridge means and independent of the vertical spacing
between said slot and the plastic surface, said metering means
including a gate displaceable between a closed position where said
gate contacts the lower surfaces of said first and second walls to
seal off said elongated slot to prevent the flow of topping
material from said hopper and an open position where said gate
contacts only the lower surface of said second wall to permit
topping material to be metered from said hopper through said
elongated slot;
d. means for agitating the topping material within said hopper and
in proximity to said elongated slot;
e. means coupled to the first wall of said hopper for vibrating
said hopper to assist in maintaining a uniform flow of topping
material through said elongated slot as said spreader is translated
back and forth across said bridge means, said vibrating means
including a rotary shaft having a plurality of spaced apart
eccentric weights and means for rotating said shaft;
f. drive means coupled to said spreader for translating said
spreader back and forth across said bridge means; and
g. control means coupled to said drive means for controlling the
back and forth translation of said spreader along said bridge
means;
whereby sequential translations of said spreader across said bridge
means followed by sequential translations of said bridge means
along the length of the plastic surface covers the entire surface
with a uniform blanket of topping material.
3. Apparatus for spreading a uniform blanket of topping material
onto a surface of plastic material having a length and a width,
said apparatus comprising:
a. a spreader including a roller assembly having first and second
spaced apart wheeled trucks for supporting said spreader and for
enabling said spreader to be translated along a linear path;
b. a hopper forming a part of said spreader for storing a supply of
loose particulate topping material and for dispensing a widthwise
stream of the topping material from an elongated rectangular slot
in said hopper as said spreader is translated back and forth along
the path, said hopper including
i. first and second converging end surfaces having parallel
oriented lower edges which define first and second opposing sides
of said slot;
ii. first and second side surfaces rigidly coupled to said first
and second end surfaces and having parallel oriented lower edges
which define third and fourth opposing sides of said slot where the
first, second, third and fourth sides of said slot lie within a
single plane;
iii. vibrator means coupled to said first end surface for inducing
substantially constant amplitude and substantially constant
frequency vibrations in said first end surface and for transmitting
said vibrations through said first and second side surfaces to
induce vibrations in said second end surface to thereby induce
vibrations in the particulate topping material in contact with the
vibrating first and second end surfaces and the first and second
side surfaces of said hoper to provide a uniform, uninterrupted
flow of topping material along the entire length of said elongated
rectangular slot;
c. flow control means coupled to said hopper and spanning the
length of said slot for dispensing a continuous widthwise stream of
topping material from said slot at a rate unrelated to the vertical
spacing between said slot and the underlying plastic surface, said
flow control means including rotating metering means positioned in
proximity to, oriented parallel to and centered about said slot for
metering the flow of topping material through said slot;
d. bridge means spanning the width of the plastic surface without
contacting the plastic surface and translatable along the length of
the plastic surface for providing an elevated path to support the
roller assembly of said spreader and to permit translation of said
spreader across a widthwise segment of the plastic surface while
maintaining said spreader vertically spaced above and separated
from the plastic surface, said bridge means including
i. guide means for engaging said roller assembly to confine said
spreader to a fixed path with respect to said bridge means as said
spreader is translated back and forth across said bridge means;
ii. a primary support element formed from an open support frame
having first and second ends;
iii. translatable bridge support means coupled to the first and
second ends of said primary support element for enabling said
bridge means to be translated along the entire length of said
plastic surface, said bridge support means including a first
translation unit coupled to the first end of said primary support
element and a second translation unit coupled to the second end of
said primary support element;
e. rotary drive means coupled to said roller assembly at a first
position on said spreader for translating said spreader back and
forth across said bridge means and coupled to said flow control
means at a second position on said spreader spaced apart from the
first position for rotating said rotating metering means; and
f. spreader control means coupled to said rotary drive means and to
said flow control means for selectively energizing and deenergizing
said rotary drive means and said flow control means;
whereby sequential translations of said spreader across said bridge
means followed by sequential translations of said bridge means
along the length of the plastic surface covers the entire surface
with a uniform blanket of topping material.
4. The apparatus of claim 3 wherein said first and second trucks
each include at least two non-steerable wheels for directing said
spreader in a straight line.
5. The apparatus of claim 3 wherein said rotary drive means
includes:
a. a first motor for rotating said rotating metering means; and
b. a second motor for energizing said vibrator means.
6. The apparatus of claim 3 further including reversing means for
reversing the direction of travel of said spreader when said
spreader reaches a predetermined position on said bridge means.
7. The apparatus of claim 3 wherein said rotary drive means forms a
part of said spreader.
8. The apparatus of claim 3 wherein said rotating metering means
includes vaned metering means having a first end penetrating
through the first side surface of said hopper and wherein said
rotary drive means is coupled to the first end of said vaned
metering means at a location outboard of said hopper.
9. The apparatus of claim 8 wherein said vaned metering means
includes:
a. a shaft having a centrally located axis of rotation; and
b. a plurality of vanes coupled to said shaft at radially spaced
apart intervals.
10. The apparatus of claim 8 wherein said spreader control means
energizes and deenergizes said vibrator means.
11. The apparatus of claim 8 wherein said rectangular slot is
positioned within a horizontal plane.
12. The apparatus of claim 8 wherein said flow control means
includes slot engagement means disposed below said slot and
including:
a. a shaft rotationally coupled to said spreader disposed below and
centered about said slot;
b. a slot engagement surface coupled to said shaft and engaging
said slot from below; and
c. means coupled to said slot engagement means for rotationally
displacing said shaft and said slot engagement surface.
13. The apparatus of claim 12 wherein at least a part of said slot
engagement means is formed in the shape of a section of the wall of
a cylindrical surface.
14. The apparatus of claim 8 wherein said primary support element
has a generally triangular cross sectional shape and incorporates a
load bearing base having first and second edges.
15. The apparatus of claim 14 wherein said guide means further
includes a first guide rail coupled to the first edge of said load
bearing base.
16. The apparatus of claim 8 wherein said vibrator means includes
at least three vibration generating elements coupled to said first
end surface at uniformly spaced apart intervals.
17. The apparatus of claim 16 wherein each of said vibrating
elements is coupled to said first end surface of said hopper at an
equal distance above said slot.
18. The apparatus of claim 8 wherein said primary support element
includes:
a. a horizontally oriented, load bearing base;
b. a horizontally oriented apex spaced apart from said base and
oriented parallel to said base; and
c. a plurality of struts extending between the base and the apex
which define first and second sides of the primary support
element.
19. The apparatus of claim 18 wherein said guide means is coupled
to the load bearing base of said primary support element and
includes a linear, vertically oriented surface for engaging and
guiding the roller assembly of said spreader.
20. The apparatus of claim 18 wherein the apex of said primary
support element is disposed below said base.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to material spreader systems, and
more particularly, to systems which include a spreader that is
translated above the surface of a plastic material which cannot
support the spreader. This application is a continuation-in-part of
U.S. patent application Ser. No. 311,674, filed Oct. 15, 1981, now
U.S. Pat. No. 4,540,312 which is a continuation-in-part of patent
application Ser. No. 170,126, filed July 18, 1980, now U.S. Pat.
No. 4,349,294, which is a continuation-in-part of U.S. patent
application Ser. No. 101,545, filed Dec. 10, 1979, now
abandoned.
2. Description of the Prior Art
A variety of different types of floor hardeners have for many years
been applied to the plastic surface of uncured concrete. Metallic
aggregate is a very finely divided hardener consisting of iron
filings. Mineral aggregate hardener (quartz) consists of
particulate minerals similar in size to commercially available lawn
and garden fertilizer. Traprock and emery rock are floor hardeners
having the largest particulate size. Miscellaneous other materials
are occasionally used as floor hardeners. Each of these floor
hardeners is comparatively expensive and may typically cost on the
order of twenty cents per pound.
Job application specifications relating to floor hardeners
typically state the required coverage density in pounds of floor
hardener per square foot of floor surface area. Metallic and quartz
aggregate floor hardeners are normally mixed with cement and
plasticizers, prebagged, and applied by hand using buckets and
wheelbarrows to transport the floor hardener around the job site.
Traprock and emery rock floor hardeners are usually hauled in bulk
to the job site, transported to the immediate vicinity of the job
site by a wheelbarrow and spread over the plastic concrete surface
with a shovel.
Application of floor hardener materials by hand or with a shovel
requires a great deal of skill and is typically possible only on
relatively narrow concrete pour widths. Even skilled construction
workers cannot achieve a uniform application rate or a high
production rate when working with the floor hardener materials
described above.
As a result of the uneven distribution achieved by manual
application techniques, a significant excess amount of floor
hardener must be applied to the plastic concrete surface to assure
that the specified minimum application density is achieved. As a
result of the high purchase cost of floor hardener materials, it
has been well known for many years that a significant cost
reduction in both labor and materials could be achieved if floor
hardener materials could be distributed at a high rate and with a
uniform application density. A reduction of only one-tenth of a
pound of floor hardener per square foot of floor area can achieve a
significant cost savings and a resulting profit increase, but has
been extremely difficult to achieve in practice using prior art
techniques.
In the past, a very limited number of contractors have
unsuccessively attempted to overcome the shortcomings resulting
from manual application of floor hardeners by conducting
experiments with domestic lawn spreader equipment. A Scotts lawn
spreader having a slotted, manually actuated gate has been used in
combination with a dual work bridge or saw horses and a pair of
spaced apart planks in an attempt to apply a mineral aggregate
floor hardener to a plastic concrete surface. Lawn spreaders were
not suitable for use with metallic aggregate since the small size
of the iron filing particles were incompatible with the lawn
spreader mixing and metering systems. The larger size aggregate
particles of traprock and emery rock aggregate wedged between the
lawn spreader agitator and hopper and jammed in the slotted gate,
rendering the device inoperative. Since mineral aggregate floor
hardener was similar in consistency to typical lawn fertilizer,
only that specific type of floor hardener could be made to function
on a rudimentary basis and on very limited pour widths with the
Scotts lawn spreader. Because the mineral aggregrate particles were
dispensed through the spaced apart, slotted apertures in the lower
portion of the lawn spreader hopper, the floor hardener material
was distributed in spaced apart rivulets, rather than the desired
uniform particulate blanket. Numerous difficulties were encountered
with steering and manually propelling the two wheel lawn spreader
device along the dual work bridge or wooden planks.
These sporadic efforts to distribute even mineral aggregate floor
hardeners with a lawn spreader were considered unsatisfactory and
were never adopted by the industry.
The prior art includes a variety of different types of material
spreaders. U.S. Pat. Nos. 2,806,435 (Mundell) discloses a suspended
refuse spreader which includes a hopper translatable along the
length of a pair of fixed, overhead rails. The hopper of this
spreader hangs below these fixed support rails and includes a
plow-like deflector which deflects the refuse into two spaced apart
piles as the spreader is translated along the rails. A cable is
attached to one end of the spreader to translate the spreader with
respect to the supporting rails.
U.S. Pat. No. 2,807,234 (Midelen) discloses an engine-driven
livestock feeding apparatus which can be translated along a pair of
fixed rails between which a livestock feed trough is positioned.
The material discharged from the lower portion of this apparatus is
separated by a deflector within the trough into two heaps so that
cattle on both sides of the rail system can be fed.
U.S. Pat. No. 1,200,393 (Neller) discloses an overhead carrier
which is translated along a single fixed overhead rail. When the
carrier reaches the desired unloading position, the hopper of the
carrier is tilted sideways to discharge the contents.
U.S. Pat. No. 3,230,845 (Mauldin) discloses a spreader which rolls
over and is supported by the surface upon which material is to be
spread. U.S. Pat. No. 3,453,988 (Trent) discloses a portable
spreader which is linearly translatable along the length of a pair
of fixed rails.
U.S. Pat. No. 2,113,503 (Belkesley) discloses a multiple-purpose
spreader which includes a hopper supported by a grouping of three
wheels. This topping spreader rolls over the area upon which
material is to be discharged.
U.S. Pat. No. 2,318,064 (Delaney) discloses a conventional
fertilizer spreader which includes a hopper and a finger agitator
rotated by the spreader wheels. A mechanically actuated gate is
positioned in the lower portion of the hopper and meters the
discharge of material from the spreader.
A wide variety of other types of relevant prior art has been cited
in each of the related patent applications identified above in the
section entitled "Field of the Invention."
SUMMARY OF THE INVENTION
Briefly stated, and in accord with one embodiment of the invention,
a material spreader system dispenses a topping material onto the
surface of a plastic substance lying within an area having a
length, width and opposing sides. The area may include a vertically
extending obstruction positioned adjacent one of the sides of the
area and extending a predetermined distance into the area. The
presence of the obstruction within the area defines a reduced width
section of the area. The material spreader system includes a
spreader having a hopper for storing a supply of topping material
and for dispensing a layer of the topping material as the spreader
is translated along a path. Bridge means having first and second
ends provides an elevated path to permit widthwise translation of
the spreader across the area. Means is coupled to the hopper for
metering the discharge of topping material from a widthwise slot in
the hopper at a rate proportional to the translation velocity of
the spreader and independent of the vertical spacing between the
spreader and the plastic surface. The metering means includes means
for agitating the topping material within the hopper. In one
embodiment of the invention, the spreader includes a hydraulic pump
for providing a source of pressurized hydraulic fluid and means for
energizing the pump. A first hydraulic motor translates the
spreader back and forth across the bridge means. Various other
hydraulic motors, valves and other elements may be provided to
operate or control various other features of the invention. In
another embodiment of the invention, the bridge means may include
means for varying the length of the bridge means to enable the
bridge means to clear the obstruction as said bridge means is
translated past the reduced width section of the area. In addition,
the bridge means may include means for varying the vertical
separation between the bridge means and the surface of the plastic
substance.
DESCRIPTION OF THE DRAWINGS
The invention is pointed out with particularity in the appended
claims. However, other objects and advantages together with the
operation of the invention may be better understood by reference to
the following detailed description taken in conjunction with the
following illustrations wherein:
FIG. 1 is a perspective view of the concrete topping spreader
system of the present invention.
FIG. 2 is a sectional view of the spreader illustrated in FIG. 1,
taken along section line 2--2.
FIG. 3 is a side view, taken from the left-hand side of the
spreader illustrated in FIG. 1.
FIG. 4 is a view from above of the spreader illustrated in FIG.
1.
FIG. 5 is a view from below of the spreader illustrated in FIG.
1.
FIGS. 6A and 6B illustrate the spreader gate and linkage which is
coupled to the lower portion of the hopper. FIG. 6A illustrates the
gate in the closed position while FIG. 6B illustrates the gate in
the open position.
FIG. 7 illustrates a second embodiment of the concrete topping
spreader of the present invention which includes a modified lateral
support structure for the air supply hose assemblies and a modified
spreader gate.
FIG. 8 is a sectional view of the spreader illustrated in FIG.
7.
FIG. 9 is a partial sectional view of the spreader illustrated in
FIG. 8, illustrating the spreader gate in the "open" and "closed"
positions.
FIG. 10 is an enlarged perspective view of one of the guideblock
assemblies illustrated in FIG. 7.
FIG. 11 is a partially cut away view from below of the spreader
illustrated in FIG. 8.
FIG. 12 is a schematic diagram of the pneumatic control and power
system for the concrete topping spreader.
FIG. 13 is a perspective view of an improved material spreader
system including adjustable bridge means having means for reducing
the span length of the bridge.
FIG. 14 schematically illustrates the configuration of the
pneumatic control and power system for the improved material
spreader system.
FIG. 15 is a partial perspective view illustrating the manner in
which the wheel and wheel mounting bracket of the improved spreader
system is coupled to an end of the bridge.
FIG. 16 is an exploded view of the spreader of the improved
material spreader system, particularly illustrating the mechanical
elements of the spreader.
FIGS. 17A-D represent a partially cutaway perspective view of the
improved material spreader system, particularly depicting the
method in which the configuration of the bridge is modified to
permit the bridge to be translated past a vertically oriented
obstruction.
FIGS. 18 and 19 illustrate the structure and operation of the
pivotable gate sections of the bridge.
FIG. 20 illustrates the manner in which the control station for the
spreader is operated to clear a vertically oriented
obstruction.
FIG. 21 illustrates the manner in which a clamp assembly is coupled
to a vertically oriented obstruction and to a horizontally oriented
track.
FIG. 22 is a partially cutaway perspective view illustrating yet
another embodiment of the material spreader system of the present
invention which includes a hydraulically powered spreader and
continuously variable bridge length adjustment means.
FIG. 23 is an exploded perspective view of the primary mechanical
component parts of the hydraulically powered spreader.
FIG. 24 is a partial perspective view of the hydraulically powered
spreader, particularly illustrating the hydraulic gate actuator
mechanism.
FIG. 25 is a schematic diagram of the hydraulic components of the
hydraulically powered material spreader.
FIG. 26 is a partically cutaway perspective view of the length
adjustment means for one span or track of the material spreader
system bridge.
FIG. 27 is an exploded perspective view of the length adjustment
means depicted in FIG. 26.
FIG. 28 is a partially cutaway perspective view of the length
adjustment means depicted in FIG. 26, showing the length adjustment
means in a partially extended position.
FIGS. 29A-F represent a series of views from above depicting the
material spreader system as it is displaced past a vertically
extending obstacle lying within the plastic surface area.
FIGS. 30A--B are partially cutaway perspective views particularly
illustrating the manner in which the material spreader system
bridge is translated past a vertically extending obstruction.
FIG. 31 depicts a pneumatic powered embodiment of a material
spreader system including a bridge fabricated from a concrete
screed frame and having collapsible end sections.
FIG. 32 is a sectional view of the material spreader system
depicted in FIG. 31, taken along section line 32--32.
FIG. 33 is an exploded perspective view of the pneumatically
powered spreader depicted in FIG. 31.
DETAILED DESCRIPTION OF THE INVENTION
In order to better illustrate the advantages of the invention and
its contributions to the art, the various mechanical features of
the preferred embodiment of the invention will now be reviewed in
detail.
Referring now to FIG. 1, a multi-section, variable length bridge 10
includes parallel bridge spans 12 and 14. Vertically oriented guide
means in the form of guide rails 16 and 18 extend along the
interior edges of bridge spans 12 and 14. Bridge 10 is supported by
a plurality of wheels 20 which are of a fully castering design to
facilitate movement and positioning of bridge 10. Bridge 10 is
fabricated in sections generally five to ten feet long. A short
single section bridge length is illustrated in FIG. 1, but multiple
bridge sections can be readily coupled together to form an overall
bridge length of sixty-five feet or longer. Bridge 10 is positioned
over the non-load bearing, plastic upper surface of an area of wet
concrete 22. Wheels 20 of bridge 10 are supported either on solid
ground, a solid previously cured concrete surface, or any other
firm, load supporting surface that form a perimeter outside the
plastic concrete surface area 22.
Referring now generally to FIGS. 1-5, spreader 24 includes four
wheels with rubber pneumatic tires which serve as spreader to
bridge coupling means. Wheels 26 are rotatably coupled to spreader
24 by axles 28 and 30 and serve to transfer the weight of spreader
24 to bridge 10. Spreader 24 includes a hopper 32 having first and
second side surfaces 34 and 36 and first and second end surfaces 38
and 40. End surfaces 38 and 40 are inclined with respect to the
vertical axis of spreader 24 and the lower ends of these end
surfaces converge to form an elongated, rectangular or widthwise
slot 42 having a pair of opposing long sides and a pair of opposing
short sides.
First and second end surfaces 38 and 40 include parallel oriented
lower edges as depicted in FIG. 2 which define first and second
opposing sides of slot 42. Side surfaces 34 and 36 are rigidly
coupled to end surfaces 38 and 40 and include parallel-oriented
lower edges which define third and fourth opposing sides of slot 42
such that all four sides of slot 42 lie within a single plane.
Because hopper 32 is rigidly interconnected with spreader 24 as
depicted in FIGS. 1 and 2, relative tilting between hopper walls
34, 36, 38 and 40 and spreader 24 is prevented.
As illustrated in FIG. 1, spreader to bridge coupling means in the
form of wheels 26 engage guide rails 16 and 18 at first and second
spaced apart intervals along the length of bridge 10. Because guide
rails 16 and 18 define parallel, linear paths along the length of
bridge 10 and because the left and right sets of spreader wheels 26
are configured to engage the vertically oriented surfaces of guide
rails 16 and 18, the spreader to the bridge coupling means or
wheels 26 function to steer spreader 24 in a straight line as the
spreader is translated back and forth along bridge 10. Although
prior art two wheel spreaders freely rotate about their axially
aligned wheels, the spreader to bridge coupling means of the
present invention engages bridge 10 at first and second spaced
apart intervals along the length of the bridge span to maintain a
fixed planar relationship between spreader 24 and the bridge. This
feature of the invention thereby maintains a fixed planar
relationship between spreader 24 and the concrete surface 22 to
provide a highly stable platform for distributing topping material
from widthwise slot 42.
Referring now also to FIGS. 6A and 6B, a gate 44 includes clam
shell doors 46 and 48. The linkage which actuates clam shell doors
46 and 48 will be discussed in detail by referring to FIGS. 5, 6A
and 6B. Rods 50 and 52 extend through the lower sidewalls 54 and 56
of spreader 24. Rods 50 and 52 are freely rotatable with respect to
sidewalls 54 and 56. A group of four standoffs 58 are rigidly
mounted to end surfaces 38 and 40 of hopper 32. Rods 50 and 52 are
freely rotatable with respect to standoffs 58. On each side of
spreader 24, a gate actuator arm 60 is rigidly coupled to rod 50
and extends vertically upward. Rotational displacement of arm 60
causes rod 50 to rotate and thereby rotationally displaces linkage
elements 62, 64, 66, 68 70, 72 and 74 as is illustrated in FIGS. 6A
and 6B. Clam shell doors 46 and 48 are rotatably coupled to
sidewalls 54 and 56 of spreader 24 by rods 76 and 78. Reinforcing
elements 80 and 82 are coupled to the lower surfaces of clam shell
gates 46 and 48 to provide additional strength and rigidity.
A flange 84 extends horizontally outward from the upper side
surfaces of spreader 24 and an actuator arm 60 extends vertically
upward through slot 86 in flange 84. Actuator arm 60 is in a
vertical position when gate 44 is closed over slot 42. In this
closed position, actuator arm 60 contacts and is stopped by the end
of slot 86. A clamp can be positioned at a predetermined distance
along the length of slot 86 in an arrangement which prevents
further movement of actuator arm 60 along the length of slot 86.
Clamps can thus be applied to flanges 84 to limit the maximum open
position of gate 44. FIG. 3 best illustrates the manner in which
pneumatic actuator 88 includes a cylinder which is secured to the
side of spreader 24. An actuator arm of actuator 88 is coupled to
gate actuator arm 60.
Referring now to FIGS. 2 and 5, a 1.3 horsepower, sixty PSI high
torque pneumatic motor 90 is coupled to end member 38 of hopper 32
by a mounting bracket 92. Motor 90 is commerically available from
the Gast Manufacturing Company of Benton Harbor, Michigan (model
number 4AM-RV-75-GR20). Sprocket wheels on the outputs drive shaft
of motor 90 and on axle 28 provide a ten to one gear reduction and
are coupled together by a drive chain 94. An additional bearing
block 96 is coupled to an inner surface of the housing of spreader
24 to more rigidly support axle 28 in the vicinity of motor 90.
Motor 90 can be operated in either a forward or a reverse direction
depending on whether pressurized air is coupled to port 98 or port
100.
A plurality of three pneumatic air vibrators 102 is coupled to end
member 40 of hopper 32 as is best illustrated in FIG. 5. When
pressurized air is supplied to the input ports of each of these air
vibrators, a weighted piston within the cylinder of each device
vibrates up and down along the vertical axis of the device. This
piston reciprocates at a rate of ten thousand cycles per minute.
Pneumatic air vibrators of this type are commercially available
from the Navco Manufacturing Company. Note that each of these
vibrators is positioned near the lowermost portion of hopper 32 and
that these vibrators are separated by a uniform spacing along the
width of hopper 32. Air vibrators 102 commence operation when
actuator 88 is operated to open gate 44. The vibrations produced by
air vibrators 102 causes the topping material within hopper 32 to
be uniformly metered from gate 44 and prevents undesired particle
build-ups in hopper 32.
Referring now to FIGS. 4 and 5, a chain 104 surrounds a pair of
sprocket wheels which are coupled to the shaft of finger agitator
106 and to axle 28. A chain guard 105 is positioned around chain
104 and serves as a protective device. Since wheels 26 are rigidly
coupled to axle 28, the linear translation of spreader 24 along
bridge 10 rotates wheels 26 and rotates vaned metering means or
finger agitator 106 at a rate directly proportional to the rate of
translation of spreader 24. Vaned metering means 106 includes a
shaft having a centrally located axis of rotation and a plurality
of vanes coupled to the shaft at radically spaced apart intervals
as depicted in FIGS. 2 and 4. Faster movement of spreader 24 causes
more rapid rotation of finger agitator 106 and a more rapid rate of
discharge of topping material from gate 44 when it is in the open
or partially open position. Thus, a uniform topping discharge
density is provided which is not affected by the rate of
translation of spreader 24.
Referring now to FIGS. 1-3, a pair of support arms 108 extend
vertically upward from the midsection of bridge 10. A pair of
coiled, flexible double passageway air hoses 110 and 112 extend
from support arms 108 to support arms 114 and 116 on spreader 24.
Double passageway air hoses 110 and 112 are routed through support
arms 108 to control station 118 on bridge 10. A source of
pressurized air (about 60 PSI, 25 C.F.M.) is coupled to control
station 118.
The pressurized air coupled to support arm 116 operates actuator 88
and pneumatic vibrators 102. The pressurized air supplied to
spreader 24 through support arm 114 is coupled to input ports 98
and 100 of motor 90. One of the two valves in control station 118
controls the air pressure directed to actuator 88 and air vibrators
102 while the second control valve regulates the amount and
direction of air coupled to motor 90. This second control valve
permits motor 90 to be operated in either forward or reverse
directions to regulate the direction of travel of spreader 24.
Varying the amount of air pressure transmitted to motor 90 can vary
the velocity of spreader 24 from a low translation speed of about
twenty feet per minute to a high translation speed of about one
hundred feet per minute.
The manner of operating and using the concrete topping spreader of
the present invention will now be described in some detail.
Generally, a three man crew is required to operate the topping
spreader in the most efficient manner. One crew member is primarily
responsible for reloading the hopper with the desired topping
material. One man operates the control station to regulate the
direction and speed of operation of the spreader across bridge 10.
The third man assists in laterally translating bridge 10 along a
length of a section of concrete over which the topping material is
to be distributed. Many different topping materials such as quartz,
mineral, metallic, traprock, and emery can be accurately dispensed
by the present system.
The desired rate of distribution of topping material is first
determined and a clamp or other similar device is positioned along
slot 86 of flanges 84. This determines the maximum open position of
clam shell gate 44. With typically used topping material, the rate
of distribution can be varied from about one-tenth of a pound of
topping material per square foot to about four pounds per square
foot. After the hopper of spreader 24 has been loaded, the operator
opens both control valves at control station 118. Actuator 88 is
thereby actuated to the open position and motor 90 commences
rotation. Rotation of motor 90 causes axle 28 to rotate which
rotates chain 104 and thus finger agitator 106. The extreme outer
edges of finger agitator 106 are positioned within about one-eighth
of an inch of side surfaces 38 and 40 of hopper 32 and serve to
wipe away any topping material which may have formed an obstruction
or bridge and, in addition, insures a free and uniform flow of
topping material through clam shell gate 44 at all times. Air
vibrators 102 commence operation when actuator 88 causes gate 44 to
open.
After spreader 24 has completely traversed the widthwise span of
bridge 10 across concrete surface 22, the spreader is stopped, the
bridge is laterally translated a distance equal to the width of
topping material previously spread and the spreader is translated
over the bridge 10 in the opposite direction. This procedure is
repeated with intervening reloading steps until the complete
surface of the wet concrete has received a layer of topping.
Referring now to FIGS. 7-12, a modified version of the concrete
topping spreader will now be described in detail. This modified
spreader embodiment illustrated in FIGS. 7-12 will be referred to
as spreader 124.
As was the case with bridge 10 depicted in FIG. 1, the
multi-section, variable length bridge 10 depicted in FIG. 7
incorporates triangular truss bridge spans 12 and 14 each having a
load bearing base for supporting wheels 26 of spreader 124. Each
bridge span includes an apex element which in the illustrated
embodiment of the invention is positioned below and centered about
the span base. The apex element is oriented parallel to the span
base. A plurality of spaced apart struts extend between the spaced
apart edges of the span base and the apex element to thereby define
the sides of the triangular truss bridge span. The triangular truss
configuration of bridge spans 12 and 14 provides a rigid, yet light
weight bridge 10 which can be fabricated in five foot and ten foot
sections as described above and assembled in the field into a
desired length of up to at least sixty-five feet as dictated by the
width of the area of plastic concrete 22. When the spreading job
has been completed, the bridge spans 12 and 14 of variable length
bridge 10 can be broken down into shorter sections compatible with
the load carrying capability of a pick-up truck or other commonly
available, short bed length vehicle.
FIG. 7 specifically indicates the manner in which dual air hoses
110 and 112 are coupled between bridge 10 and spreader 124. On each
side of bridge 10, a pair of outriggers 126 and 128 extend
laterally outward and are coupled together by a tightly stretched
support cable 130. FIG. 10 specifically indicates that a plurality
of laterally translatable guideblocks 132 are coupled at evenly
spaced apart intervals to air hose 110. As illustrated in FIG. 10,
a clamp 134 is coupled to the lower portion of guideblock 132 and
includes a pair of cylindrical apertures through which each
individual air hose of the dual air hose assembly 110 can be
routed. The free end of air hose 110 is coupled to spreader 124 by
support 116. The guideblocks are laterally translated back and
forth across bridge 10. Air hose 112 is coupled to bridge 10 in a
similar manner.
Both air hoses 110 and 112 are coupled to a control panel 118.
FIGS. 7 and 12 indicate that an air input hose 136 is coupled to
master on/off valve 138. Pneumatic valve 150 is coupled to control
assembly 118 and air hose 112 and serves as a motor throttle valve.
Actuating valve 150 to provide pressurized air to one of the two
hoses of hose assembly 112 causes motor 90 to rotate in a forward
direction. Controlling the rate of air flow through valve 150
varies the operating speed of motor 90. When pressurized air is
coupled by valve 150 to the second air hose of air hose assembly
112, motor 90 rotates in a reverse direction at a rate controlled
by the amount of air flow provided.
Control valve 152 in control unit 118 actuates air vibrators 102
and the two pneumatically controlled gate position control
cylinders 140. In the first position, valve 152 directs pressurized
air through one of the two air hoses in hose assembly 110, causing
the shafts of the two air actuator cylinders 140 to be retracted
into the position illustrated in FIG. 9. As indicated in FIG. 9,
shaft 142 and pneumatic actuator 140 are coupled to slot engagement
means or gate 144 which pivots or rotates about shaft 146 into an
open position which establishes a gap indicated by reference number
148 between side surface or first end wall 40 and the smoothly
curved cylindrical section which forms the upper surface of gate
144. When control valve 152 is moved into the "off" position, air
pressure is removed from the hose which supplies air under pressure
to air vibrators 102 and is routed instead to the second air
pressure port of actuator cylinders 140. In the "off" position
valve 152 directs pressurized air through the second hose of air
hose assembly 110 which actuates pneumatic actuator 140 and causes
shafts 142 to extend. Extension of shafts 142 rotates gate 144 into
the "closed" position and terminates the flow of material through
widthwise slot 42 of spreader 124. In FIG. 9, the dotted lines
indicate the "closed" position of gate 144.
Referring now to FIGS. 9 and 11, an adjustable mechanical stop 153
limits the maximum gate displacement into the "open" position to
thereby control the rate at which topping is dispensed as spreader
124 is laterally translated. In the preferred embodiment of the
present invention, a one inch diameter threaded rod 154 passes
through an aperture cut in the lower end wall of the base of
spreader 124. A nut 155 is welded to the exterior surface of the
base of spreader 124 and causes rotation of rod 154 to displace the
end of rod 154 fore and aft with respect to the side of gate 144. A
second bolt is welded to the exterior end of rod 154 to permit stop
153 to be readily adjustable by means of a wrench. A hollow tubular
support bracket 156 is welded to the interiorside surface of the
base of spreader 124. Bracket 156 both supports and guides rod 154
and serves to maintain rod 154 in a fixed vertical position with
respect to gate 144.
In order to simplify the drawings, only a portion of stop 153 is
illustrated of FIG. 9 and only one of the two stops actually used
in the preferred embodiment of the present invention is illustrated
in FIG. 11. It should be understood that a second stop is provided
on the opposite side of the base of spreader 124 so that the one
stop abuts each end of gate 144. Generally it will be desireable to
either weld a flat plate to gate 144 at the point at which the end
of stop 153 will strike the gate or alternatively to form a notch
on the end sections of gate 144 so that each end of stop 153 will
strike a surface substantially perpendicular to the end of rod
154.
It is generally desirable to fabricate the inclined end walls 38
and 40 of the spreader at an angle approaching 45.degree.. The
vibrations produced by air vibrators 102 cause end wall 40 to form
a vibrating feeding surface which prevents the topping material
contained within the hopper from adhering to this vibrating surface
and insures that the topping will flow downward along end surface
40 smoothly and evenly through the gap 148 formed in widthwise slot
42. Finger agitator 106 also assists in providing a uniform flow of
topping through gap 148 by maintaining the topping material in a
fluffed or agitated state. This fluffing action provided by finger
agitator 106 prevents compaction of the topping material which in
many circumstanced would cause an uneven and irregular flow of
topping material.
The outer slot engagement surface of slot engagement means 144 is
formed in the shape of a section of the wall of a cylinder and
rotationally engages the lower surfaces of end walls 38 and 40
which define widthwise slot 42. The unique rotary wiping action of
slot engagement means 144 provides a self-cleaning action which
prevents topping material from adhering to the leading edge of the
slot engagement surface. As slot engagement means or gate 144 is
rotationally displaced into the closed position by actuator
cylinders 140, the rotating scraping action between the lower edge
of end wall 40 and the curved slot engagement surface wipes away
topping material from the leading edge of that surface. As depicted
in FIG. 8, the curved slot engagement surface is formed in the
shape of a section of the wall of a cylindrical surface.
Stop 153 must be adjusted to the desired setting before the
spreading operation is commenced. For many standard types of
topping material, the two stops are adjusted so that 1/8" gap is
established at gap 148 when gate 144 is in the open position. The
dimension of gap 148 must always be greater than the diameter of
the material to be spread.
Continuously maintaining the self-cleaning lip of gate 144 in a
clean condition, the ability to precisely control the dimension of
gap 148, the continuous vibration of end wall 40, and the constant
translation velocity of spreader 124 enables the present invention
to uniformly spread topping material with a distribution accuracy
of two to three percent which has previously been unobtainable by
any prior art device or technique.
The method of operation of the present invention will now be
discussed in detail. First, the hopper is filled with the desired
topping material. Motor throttle valve 150 is actuated to propel
spreader 124 in the desired direction and at the desired velocity.
As the spreader passes above the beginning of the wet concrete
surface, control valve 152 is actuated, causing actuator cylinders
140 to snap gate 144 into the desired open position which is
determined by stops 153 which have been previously adjusted. In a
typical application, stops 153 will be adjusted to provide a 1/8"
gap 148. Under normal operation, a single pass of spreader 128
across bridge 10 will distribute topping at the rate of 1/4 pound
per square foot. If an applica- of one pound per square foot is
desired, spreader 12 must make four sequential passes over the same
area of wet concrete. The topping is thus distributed in four
separate blankets which has been found to produce far superior
results than can be attained by a single higher topping
distribution rate pass. At the end of the fourth pass, bridge 10 is
laterally translated so that spreader 124 can then be translated
across the next section of wet concrete four more times. To produce
an application rate of 11/2 pounds per square foot, six passes of
spreader 124 over the wet concrete would be provided.
It will be apparent to those skilled in the art that the concrete
spreader system disclosed above may be modified in numerous ways
and may assume many embodiments other than the preferred forms
specifically set out and described above. For example, a separate
wheel could be coupled to the shaft of finger agitator 106 in a
manner which would permit it to contact the surface of spans 16 and
18 of bridge 10. In this embodiment, finger agitator 106 rotates at
a rate proportional to the spreader translation velocity.
Additionally, the spreader may be powered by a gas, electric or
hydraulic motor and controlled by a computer or by remote control
means receiving radio or optical control signals. Numerous other
structural and operational modifications would be readily apparent
to one skilled in the art. The concrete topping spreader system of
the present invention can be used to spread various types of
topping materials over many different types of surfaces and does
not require an elevated bridge of the specific type disclosed.
Referring now to FIGS. 13-21, a significantly improved and more
sophisticated material spreader system is disclosed. This improved
spreader system is designed to dispense a topping material onto the
surface of a plastic material such as uncured concrete which is
lying within an area having a length, width and opposing sides. At
many job sites, the area of plastic material may include a
vertically extending obstruction such as a column which penetrates
a predetermined distance into the side of the area. Great
difficulty has been encountered in efficiently and economically
dispensing a topping material over an area which includes a number
of vertical obstructions of this type. When using material
spreaders of the type disclosed in FIGS. 1-12 above, awkward and
difficult techniques such as skewing the bridge deck to spread
topping material over plastic concrete lying between a pair of
spaced apart columns has proven to be less than satisfactory.
Significant amounts of additional time and effort are required to
utilize these techniques and to then reposition the spreader/bridge
assembly on the opposite side of these vertical obstructions. When
vertical obstructions are present on a job site, job completion
times and labor expenses are drastically reduced by utilizing the
material spreader system illustrated in FIGS. 13-21.
Referring initially to FIGS. 13-16, one embodiment of a material
spreader system adapted to dispense a topping material over an area
including a vertical obstruction will now be described in
detail.
As is readily apparent from FIG. 16, material spreader 200 is
substantially similar in design to material spreader 124 described
above and illustrated in FIGS. 7-9 and 11. In FIG. 16, the elements
of material spreader 200 have been designated with reference
numbers corresponding to reference numbers utilized in connection
with the description above of material spreader 124. Material
spreader 200 has been provided with a hopper cover 202 which
includes an open rectangular grate or screen which assists in
separating or breaking up the topping material as the topping
material is loaded into the hopper of material spreader 200. In
addition, material spreader 200 has been provided with a set of
four flanged wheels 204 which couple material spreader 200 to
bridge means 206 which is illustrated in FIG. 13. A square tube
agitator 208 may be substituted for finger agitator 106 if
particularly large size topping material is to be dispensed from
the spreader.
FIGS. 13 and 14 illustrate that air hoses 110 and 112 are coupled
to take up reels 210 and 212 which are spring biased to minimize
slack in the air hoses coupling reels 210 and 212 to spreader 200
as spreader 200 is translated from one end of bridge 206 to the
opposite end and back. FIG. 14 illustrates the manner in which
spreader 200 is energized and controlled and corresponds to the
structure depicted and described in connection with FIG. 12.
Referring now to FIGS. 13, 15, and 18-20, the adjustable bridge
means 206 of the present invention will be described in detail.
Bridge 206 includes first and second spaced apart spans 214 and 216
which engage the four flanged wheels 204 of spreader 200 and
provide an elevated path to permit widthwise translation of
spreader 200 across an area of plastic concrete or other surface
over which topping material is to be dispensed.
FIGS. 13 and 20 illustrate that control valves 150 and 152 are
positioned within a control station 218 which is rotatably coupled
to the lower end section of span 216. A locking pin 220 maintains
control station 218 in a normal or "extended" position depicted in
the left side of FIG. 20 or in the "retracted" or obstruction
clearance position depicted in dotted lines in the right side of
FIG. 20. Control valves 150 and 152 are operative when control
station 218 is in either the extended or retracted position.
Referring now to FIGS. 13, 15, 18 and 19, the span length reducing
means of bridge 206 will now be described in detail. Each end of
spans 214 and 216 of bridge 206 includes pivotable gate sections
222 and 224, each of which includes a vertically extending stop 226
which prevents spreader 200 from being translated beyond either end
of bridge 206. Each side of gate sections 224 and 226 includes a
three-element hinge 228 and a removable hinge pin 229 which couples
the gate sections to the bridge spans. (See FIG. 18) FIG. 19
illustrates that the outer hinge pin has been removed from gate
section 224, permitting that gate section to be swung in a
clockwise direction into an inboard retracted position shown.
Removal of hinge pin 229 from hinge 228 on the opposite side of
gate section 224 permits counterclockwise rotation of that gate
section over clamp 232 into an outboard retracted position. Gate
section 222 includes identical double hinge structure and can also
be pivoted into either an inboard or outboard retracted
position.
The vertical dimension of gate sections 222 and 224 is less than
the vertical dimension of bridge spans 214 and 216 to provide
clearance between these gate sections and other structural elements
of the spreader system. An auxiliary stop 230 is bolted to the
hinged junction between the gate sections and the bridge spans when
the gate sections are in the retracted position illustrated in FIG.
19 since stop 226 will have been laterally displaced from the path
of wheels 204 and will no longer provide the required stopping
feature to prevent inadvertent damage to the equipment.
The material spreader system of the present invention also includes
translatable bridge support means which is best illustrated in
FIGS. 13, 15, 18 and 19. A clamp 232 is coupled to the lower end
section of both ends of bridge spans 214 and 216 and receives each
of a pair of wheels 234 and wheel mounting brackets 236. Each end
of bridge 206 includes a pair of clamps 232, wheels 234 and wheel
brackets 236 which are collectively referred to as a first support
means or a first roller assembly. A first roller assembly supports
each of the two ends of bridge means 206 and permits the bridge to
be translated along the length of the area over which topping
material is to be dispensed. Wheels 234 are fully castering
pneumatic tire and wheel assemblies of the type described in
connection with the spreader depicted in FIG. 7.
The translatable bridge support means of the present invention
further includes second means for supporting an end of bridge means
206 as the bridge means is translated along a reduced width section
of the area over which topping material is to be dispensed. In the
preferred embodiment of the present invention, this second support
means includes a second roller assembly which is coupled to each
end of spans 214 and 216 of bridge 206. Each element of the second
roller assembly includes a small wheel 238, a vertically oriented
screw jack assembly 240 which is coupled to tubular clamp 232, and
a jack handle. Screw jack assembly 240 is actuated to elevate wheel
238 above the surface of the plastic concrete over which the
material spreader system is translated to permit the first roller
assembly to support the bridge as the material spreader system is
being laterally translated across the full width section of the
area of plastic concrete.
Referring now to FIG. 21, roller support means 244 includes a clamp
assembly 246 which is coupled around and securely attached to a
vertically oriented obstruction in the form of a column 248. Clamp
246 is fabricated from rectangular plates 254, threaded rods 260
and wingnuts 262. A horizontally oriented channel shaped track 250
is coupled to and supported by clamp assembly 246. Clamp assembly
246 includes telescopic adjustment structure which permits the
lateral spacing between track 250 and column 248 to be varied as
desired so that track 250 can readily engage wheels 238 of the
second roller assembly. This telescopic adjustment structure
comprises hollow rectangular tubes 256 to which slide tubes 258 are
coupled. The set bolts located in the top of tubes 256 lock slide
tubes 258 in the desired position with respect to column 248.
Alternatively, structure may be provided to telescopically or
otherwise adjust either the length of spans 214 and 216 or the
relative lateral position of screw jack assembly 240 with respect
to spans 214 and 216. The telescopic adjustment feature
accommodates either difference in the lateral spacing between pairs
of spaced apart columns 248 at a particular job site or
accommodates different lateral spacings encountered at various
different job sites.
The manner in which the material spreader system is utilized to
spread a uniform layer of topping material over an area including
full width and reduced width sections of the type described above
will now be described in detail primarily by reference to FIGS. 13
and 17A-D. FIG. 13 and FIG. 17A depict the configuration of the
material spreader system which is typically utilized to support the
material spreader in an elevated position above an area of plastic
concrete. Wheel mounting brackets 236 are coupled to bridge spans
214 and 216 and extend outward a length sufficient to permit wheels
234 to contact an underlying supporting surface 252 adjacent to,
but outside of the area of, plastic concrete. Wheels 238 are
elevated above the surface of plastic concrete so that the entire
bridge assembly is supported by and laterally translated by wheels
234. When a vertical obstruction such as column 248 is approached,
clamp assembly 246 together with track 250 is coupled to the column
such that the lowest part of the entire clamp/track assembly is
elevated at least slightly above the upper surface of the plastic
concrete surface.
As column 248 is approached, the spreader is moved away from the
end of bridge 206, hinge pin 229 is removed and gate section 224 is
rotated into the retracted position illustrated in FIG. 19.
Auxiliary stop 230 is bolted into place and the entire bridge
assembly is translated closer toward column 248. FIG. 17B
illustrates that the bridge assembly is then translated toward
column 248 so that screw jack assembly 240 can be actuated to cause
wheel 238 to engage track 250 and thereby elevate wheel 234 above
surface 252 which had previously supported the weight of bridge
span 216. Once the weight of span 216 is properly supported by
track 250, the securing means of clamp 232 are loosened and the
assembly comprising wheel 234 and wheel mounting bracket 236 is
completely removed from span 216 as is depicted in FIG. 17C.
Depending on the relative positioning of columns 248, the operation
depicted in FIGS. 17A-17C will take place either sequentially at
one end of the bridge followed by the other end of the bridge, or
will take place simultaneously when the columns are in paired,
spaced apart alignment. In situations where only one side of the
area to which topping material is to be applied includes vertically
oriented obstructions, the procedures depicted in FIG. 17 will be
accomplished for only a single end of bridge 206.
When the configuration depicted in FIG. 17C has been achieved, the
bridge will be translated further along the length of the area of
the plastic concrete until the spreader is properly aligned to
dispense an additional layer of topping material. Bridge 206 can be
translated back and forth along the entire length of track 250 as
required. When bridge 206 is translated into the position
illustrated in FIG. 17D, the assembly consisting of wheel 234 and
wheel mounting bracket 236 is reinstated into clamp 232 and
properly adjusted and secured. Jack screw assembly 240 is then
actuated to transfer the weight from wheel 238 back to wheel 234.
As bridge 206 is translated further along the length of plastic
concrete, the procedure described immediately above is repeated to
support the same end of span 214 above the concrete surface.
Typically, with a track of the length and configuration depicted in
FIG. 17, only a single span of bridge 206 will be supported by the
clamp assembly/track at one time.
Although only a single embodiment of the improved material spreader
system has been described, it would be readily apparent to one of
ordinary skill in the art to produce a wide variety of structural
modifications to this invention which would be equivalent to the
invention described above. For example, a clamp assembly could be
coupled to colum 248 at a point above the spans of bridge 206 and
could be engaged by a second support assembly extending upward from
the bridge. In another embodiment, translatable bridge support
means in the form of a ceiling mounted crane could be coupled by a
grouping of cables to bridge 206. When a vertical obstruction such
as a column is approached as the ceiling mounted crane is
translated along the length of the area of plastic concrete, the
adjustable bridge means could be actuated to reduce the length of
the bridge spans, permitting translation of spreader 200 over the
reduced width section of the area of plastic concrete. Another
readily apparent modification of the present invention involves
substituting rollers for wheels 234 to permit the bridge means to
be translated along and supported by the forms surrounding the area
of plastic concrete.
The bridge disclosed in connection with the preferred embodiment of
the present invention could also take many different forms other
than the specific embodiment described above. Rather than having
the pivotable gate sections which permit the span length of the
bridge to be increased and decreased as desired, removable end
sections, telescopic adjustment features for various other elements
of the bridge spans or numerous other types of length adjustment
devices could be incorporated into a bridge assembly and still fall
within the scope of the present invention. Furthermore, a bridge
assembly for supporting a translatable spreader may take the form
of a single rail and the spreader could be coupled above, below or
on both sides of that rail.
While the material spreader system has been described in connection
with dispensing topping material onto a plastic concrete surface,
the same invention could be used without modification to dispense a
topping material onto a built up roof or onto any other surface
which requires a topping or coating material but which cannot
permit the wheels of a conventional spreader to contact the surface
to be coated with topping material.
Accordingly, it is intended by the appended claims to cover all
readily apparent modifications of the invention which fall within
the broad scope of the material spreader invention. Referring now
to FIGS. 22-30, yet another embodiment of the material spreader
system of the present invention will be described in detail. This
spreader system includes a spreader having a totally self-contained
hydraulic system. In addition, the bridge of this embodiment of the
material spreader system includes structure for readily adjusting
the vertical spacing between the bridge and the surface of the
plastic substance. The bridge also includes telescopically
adjustable end sections for providing continuous adjustment of the
overall bridge length.
Referring initially to FIGS. 22-25, one embodiment of a
hydraulically powered material spreader system adapted to dispense
a topping material over an area including a vertical obstruction is
disclosed.
A material spreader 300 includes a material hopper 302 for storing
a supply of topping material. A removeable hopper grate 304
includes a screen-like sieve for breaking clumps of topping
material as the material is dispensed from a bag or other container
into hopper 302. A bag cutting blade 306 may be secured as shown to
grate 304 to assist in tearing open a bag of topping material.
The inclined sides of hopper 302 converge at the lower section of
the hopper to form a widthwise slot of the type disclosed in detail
in FIGS. 8 and 9. A gate 308 is fabricated from a cylindrical
section and can be displaced between first and second positions to
alternately cover and uncover the widthwise slot of the hopper.
FIG. 24 illustrates that a hydraulic cylinder 310 is couled to an
actuator arm 312 of gate 308. A threaded coupling in actuator arm
312 permits adjustment of the "open" position gate 308 to vary the
rate of material dispensed from the hopper 302 as spreader 300 is
translated back and forth across the bridge.
Spreader 300 includes a first pair of flange wheels 314 and a
second pair of flanged wheels 315 which engage first and second
spaced apart tracks or spans 316 and 318 of bridge 320.
Flanged wheels 314 are rigidly coupled together by a drive shaft
322 which is rotatably coupled to spreader 300 by a pair of spaced
apart bearing assemblies, such as bearing assembly 324. Flanged
wheels 315 are coupled together by second rigid shaft 326 which
also serves as a finger agitator. Drive shaft/finger agitator 326
passes through the lower interior section of hopper 302 and serves
to rigidly couple toghether the pair of spaced apart flanged wheels
315 and to act as a finger agitator to fluff up the particulate
topping material stored within hopper 302.
Referring now also to FIG. 25, energizing means such as a five
horsepower gasoline engine 328 includes an output shaft 330 which
is coupled to operate a vane double section hydraulic pump 332 of
the type manufactured by the Sperry-Vickers Company. Pump 332
comprises part of an open loop hydraulic system and produces two
independent pressurized fluid outputs designated by reference
numbers 334 and 336. A hydraulic reservoir 338 serves as a source
of hydraulic fluid which is used by the spreader hydraulic system.
In FIG. 25, standard schematic diagram symbols have been utilized
to show the specific configuration and coupling of each hydraulic
component part of the hydraulic system of spreader 300. A throttle
cable 340 permits the operating RPM of engine 328 to be controlled
from a readily accessible location.
The particulate contents of hopper 302 are vibrated by an
eccentrically weighted vibrating element taking the form of a shaft
342 to which a plurality of spaced apart, eccentric weights 344 are
rigidly secured as depicted in FIG. 23. The output shaft of a small
hydraulic motor 346 is directly coupled to shaft 342. The entire
vibration generating mechanism is coupled to the interior inclined
hopper sidewall at a location analogous to the location of the
vibration generating elements depicted in FIG. 8. FIG. 25
illustrates that output 336 of hydraulic pump 332 is coupled to a
pressure relief valve 348, to a flow control valve 350, and to
on/off valve 352. Flow control valve 350 can be adjusted to
regulate the operating speed of hydraulic motor 346 to thereby
control the intensity and frequency of the vibration imparted to
the contents of hopper 302. Valve 352 either activates or
deactivates hydraulic motor 346 to energize or deenergize the
hopper vibrating system.
The second output 334 of hydraulic pump 332 is coupled to a
pressure relief valve 334 and to an on/off valve 356. Valve 356 is
actuated by actuator arm 358 (see FIG. 23) which can be
conveniently reached by an operator standing at either side of
spreader 300. When engine 328 is operating, displacement of valve
356 into the "on" position provides pressurized hydraulic fluid to
hydraulic cylinder 310 for opening gate 308. Actuation of valve 356
into the "on" position also transmits pressurized hydraulic fluid
through flow control valve 360 and forward/reverse valve 362 to
motor 364. Motor 364 is coupled by a pair of sprockets and a drive
chain designated by reference number 366 to rotate drive shaft
322.
Referring now to FIGS. 22, 23 and 25, sensing means is provided to
sense the position of spreader 300 along the length of bridge 320
and to generate a reversing signal when spreader 300 arrives at a
predetermined location along bridge 320. Reversing means is coupled
to the sensing means and to hydraulic motor 364 for reversing the
flow of hydraulic fluid through motor 364 in response to the
reversing signal. The sensing means includes a reversing bracket
368 which is coupled to bridge 320 to permit engagement by
reversing bracket engaging means in the form of a forked actuator
arm 370. An overcenter locking device 372 includes a biasing spring
374 which maintain actuator arm 370 in either a first or second
position until actuator arm 370 is displaced in to the opposite
position by engaging a reversing bracket 368. The two arms of
actuator arm assembly 370 are laterally offset along actuator arm
shaft 376 so that actuator arm 370 will be engaged by only one
specific reversing bracket 368. Typically a first reversing bracket
368 is coupled in proximity to one end of bridge 320, while a
second reversing bracket 368 is coupled in proximity to the
opposite end of bridge 320. The arms of these two reversing
brackets 368 are laterally offset to engage a specific arm of
forked actuator arm 370.
As illustrated in FIG. 25, the shaft 376 of actuator arm 370 is
coupled to a pilot valve 378 which tranmits pressurized hydraulic
fluid to either input port 380 or 382 of flow switching valve 362.
The transmission of pressurized hydraulic fluid from pilot valve
378 to a specific one of the input ports 380 or 382 causes
pressurized hydraulic fluid to flow through motor 364 in either a
first or a second direction which determines whether spreader 300
is translated in either a first or a second direction across bridge
320.
When valve 356 is displaced into the "off" position, hydraulic
cylinder 310 is deenergized, causing gate 308 to close and seal off
the widthwise slot in the lower portion of hopper 302. The flow of
hydraulic fluid to hydraulic motor 364 is also terminated and the
movement of the spreader is stopped. Flow control valve 360 can be
adjusted to vary the translation velocity of spreader 300 to assist
in achieving a desired material distribution density.
Referring now to FIGS. 22, 26-28 and 30, the bridge length
adjustment means which permits the material spreader system of the
present invention to continue operating within a reduced width
section will now be described in detail. Many of the reference
numbers to be used in connection with the description of the
structure disclosed in FIGS. 22, 26-28 and 30 have previously been
used in connection with FIGS. 17 and 21 and indicate structural
elements of the embodiment now under discussion which performs
substantially identical functions as those elements described
previously.
When the material spreader system of the present invention is being
utilized to spread topping material over the full width section of
a plastic surface, the first support means of the first and second
bridge translation units (indicted by reference Nos. 234, 236, 238,
240 and 398) is utilized to contact a supporting surface lying
outside of the area of plastic material for the purpose of
supporting the bridge. This first support means 383 includes a pair
of telescopically adjustable wheel mounting brackets 236 which are
coupled to each end of the bridge and which each include a fully
castering wheel 234. Wheel mounting brackets 236 are telescopically
adjusted to an appropriate point and locked into position by a
plurality of set bolts as discussed earlier.
FIGS. 29 and 30 depict a detailed illustration of the manner in
which second support means 385 which is coupled to each end of the
bridge can be utilized to support one or both ends of the bridge
can be utilized to support one or both ends of bridge 320 above the
plastic surface as the bridge is laterally translated past a
reduced width section of the plastic surface which includes a
vertically oriented obstruction such as a column 248. Second
support means 385 includes wheel 238, screw jack assembly 240 and
roller support means indicated generally by reference No. 244. As
discussed in detail above, roller support means 244 includes a
clamp assembly 246 and a horizontally oriented track 250 which
receive and support screw jack assembly 240. In the improved
version of bridge 320 presently under discussion, screw jack
assembly 240 is rotated into the horizontal position depicted in
FIG. 30A when not in use and is rotated into the vertically
oriented position depicted in FIG. 30B for the purpose of engaging
track 250. When the weight of a selected portion of bridge 320 has
been transferred to screw jack assembly 240, wheel mounting bracket
236 together with wheel 234 are removed from that segment of bridge
320.
The length of tracks 316 and 318 which support flanged wheel sets
314 and 315 of spreader 300 can be continuously varied by sliding
the telescopically adjustable track section 384 and 386 either
toward or away from the end of brige 320 as illustrated. FIGS.
26-28 depict the specific structural elements which are utilized to
form track sections 384 and 386 and to permit telescopic adjustment
of those track sections with respect to bridge 320. Each track
section 316 and 318 includes a vertically oriented spreader stop
bracket 388 which is coupled to a telescoping track element 390. A
securing bracket is coupled to the side support element 393 of
bridge 320 and supports track element 390 from below. A sufficient
gap is maintained between the lower surface of track 316 and
securing bracket 392 to permit track element 390 to be
telescopically adjusted as required. Each end of bridge 320
includes telescopically adjustable track sections 384 and 386.
These telescopic track sections are fabricated so that the overall
length of bridge 320 can be adjusted to clear any vertically
oriented obstructions of the type typically encountered.
FIGS. 29A-F sequentially depict the manner in which the weight of
bridge 320 can be transferred from wheel 234 and wheel mounting
bracket 236 to wheel 238 and screw jack assembly 240. FIGS. 29A and
B depict track section 386 in the extended position, while FIGS.
29C and D depict track section 386 in the retracted position. FIG.
29F depicts the configuration of bridge 320 after it has been
translated past vertically oriented obstruction 248. In this
"normal" operating configuration, screw jack assemblies 240 have
been rotated back into the horizontal or stored position, the
weight of the depicted end of bridge 320 is being supported by
wheels 234 and track sections 384 and 386 have been telescopically
extended on an appropriate length to permit spreader 300 to
dispense topping material right up to the edge of the plastic
concrete surface.
Referring now to FIG. 22, means for varying the vertical separation
between bridge 320 and the surface of the plastic substance will
now be described in detail. A pair of vertically oriented end
plates 394 are coupled to each end of bridge 320. A single bridge
translation unit which includes wheel 234, wheel mounting bracket
236, wheel 238 and screw jack assembly 240, is coupled to one of
the two end plates 394. By removing the grouping of three securing
devices designated by reference number 396 from both the front and
back surfaces of each translation unit mounting bracket 398,
bracket 398 can be vertically adjusted with respect to end plate
394 and coupled at any given elevation to bracket 394. Adjustment
of all four mounting brackets 398 of bridge 320 permits the overall
elevation of bridge 320 to be controlled as desied to thereby vary
the vertical separation between spreader 300 and the surface of the
plastic substance on which topping material is to be distributed.
Any one of a number of different variables may dictate that
spreader 300 be either closer to or further away from the surface
of the plastic substance to achieve optimum material distribution
onto that plastic surface.
The vertically oriented support arms 400 and the various lengths of
cross bracing 402 provide extra support and rigidity to bridge 320.
The entire bridge assembly is bolted together and can be readily
disassembled for storage or transportation to another job site. The
side sections 404 of bridge 320 are fabricated in sections and are
joined together by securing means as is indicated by reference
number 406.
It can now be seen that the spreader disclosed above which includes
a totally self-contained hydraulic system operates automatically to
repeatedly traverse bridge 320 for the purpose of distributing
topping material onto a plastic surface. In order to achieve the
most uniform possible distribution, spreader 300 typically traverse
bridge 320 approximately four or more times before bridge 320 is
laterally displaced along the length of the plastic surface. After
the desired number of passes has been completed by spreader 300,
the spreader operator actuates arm 358 which deenergizes spreader
drive motor 364 and closes gate 308. Bridge 320 is then laterally
displaced a distance approximately equal to the length of the
widthwise slot in the hopper 302.
It will be apparent to those skilled in the art that the materials
spreader system disclosed above may be modified in numerous ways
and may assume many embodiments other than the preferred forms
specifically set out and described above. For example, many
different hydraulic system configurations could be utilized to
achieve substantially the same result that is achieved by using the
specific configuration of hydraulic components disclosed above. In
addition, totally different means for reversing the direction of
travel of the spreader could readily be adapted to operate with the
specific embodiment of the invention disclosed above and would be
obvious to one of ordinary skill in the art. Numerous other types
of modifications would be readily apparent to one skilled in the
art. Accordingly it is intended by the appended claims to cover all
such modifications of the invention which fall within the broad
scope of the material spreader invention disclosed above.
Referring now to FIGS. 31, 32 and 33, yet another embodiment of the
material spreader system of the present invention will be described
in detail. Spreader 400 of this version of the material spreader
system is structurally quite closely related to spreader 24
depicted in FIGS. 1 and 2 and to spreader 124 depicted in FIGS. 7,
8, 9, 11 and 12. Spreader 400 includes a hopper 402 having an
elongated slot 404 which is selectively exposed by a clam shell
gate mechanism 406. A pneumatically powered actuator 408 displaces
gate 406 between an "open" and a "closed" position. A plurality of
three pneumatically powered vibrators 410 are coupled to an
inclined side wall of hopper 402 for the purpose of forming a
vibrating particulate feed surface.
Drive means in the form of a pneumatically powered motor 412 is
coupled to spreader 400 for the purpose of translating the spreader
back and forth along the length of bridge means 414. The output
shaft of motor 412 is coupled to a drive sprocket 416 which engages
a drive chain 418.
In this particular embodiment of the invention, bridge means 414 is
fabricated from a standard, commercially available open support
frame of the type typically used in connection with a triangular
truss concrete screed. A suitable screed frame is available from
the Allen Engineering Corporation of Paragould, Arkansas. The
triangular truss frame includes a generally triangular cross
section having an upper apex formed from a top support member 420.
The sides and base of the triangular frame are defined by a
plurality of truss members designated generally by reference number
422 in FIG. 32. The intersection of the sides and base of the
triangular frame further define first and second edges designated
by reference numbers 424 and 426. First and second spreader support
rails designated by reference numbers 428 and 430 are coupled by a
plurality of mounting brackets 432 to frame mounting brackets
designated by reference number 434. When the triangular truss frame
is used as a screed, frame mounting brackets 434 are utilized to
couple front and rear screed blades to the screed. In the material
spreader system embodiment depicted in FIGS. 31, 32 and 33, frame
mounting brackets 434 couple the triangular truss frame to the
remaining elements of bridge means 414.
A roller assembly 436 includes first and second spaced apart trucks
438 and 440. Each truck includes an axle 442 and first and second
wheels 444. Wheels 444 are rigidly coupled to axles 442. The
central section of each axle 442 includes a drive sprocket 446.
Displacement of drive chain 418 caused by rotation of motor 412
rotates drive sprockets 446, axles 442 and wheels 444. Actuation of
motor 412 in either a forward or a reverse direction thereby causes
either forward or reverse translation of spreader 400 with respect
to bridge means 414. The speed and direction of operation of motor
412 is controlled in the manner described above in connection with
FIGS. 1-12. The pneumatic flow diagram depicted in FIG. 12 shows
the manner in which a supply of pressurized air is transmitted to
the various pneumatically powered operating elements of spreader
400. FIG. 31 illustrates that the motor throttle valve and gate
control valve are positioned within a control box 448. It is
apparent that the control valves shown depicted within control box
448 could readily be included within spreader 400 and actuated by
radio waves or optical signals manually or automatically actuated
by position sensing means to permit operator control of the
spreader from a position outside of the wet concrete surface
area.
Spreader 400 is provided with a supply of compressed air by two
sets of paired air hoses 450 and 452 and by associated spring
biased hose supply reels 454 and 456 in a manner similar to that
described above in connection with the material spreader system
depicted in FIG. 13.
An idler shaft 458 includes a drive sprocket 460 which is rotated
by displacements of drive chain 418. Rotation of idler shaft 458
causes displacement of a second drive chain 462 which is coupled to
rotate finger agitator 464.
Translatable bridge support means in the form of wheeled
translation unit 466 is coupled to each end of bridge means 414.
The structure and function of primary wheel unit 468 and secondary
wheel unit 470 is substantially the same as that described earlier
in connection with FIGS. 17A-B, 21, 22, 29A-D and 30A-B.
Bridge means 414 further includes swinging end sections 472 and 474
which are coupled by a hinge 476 to translation unit 466. When the
material spreader system is being translated past a vertically
oriented obstruction such as a warehouse column, end sections 472
and 474 are placed in the retracted position designated by
reference number 472. A stop bracket 478 includes a horizontally
oriented coupling bar and two locking pins which extend vertically
downward. The two locking pins of stop bracket 478 are inserted
into apertures in the upper surface of the ends of support rails
428 and 430 and limit the maximum displacement of spreader 400 with
respect to bridge means 414. When end sections 472 and 474 are
moved into the extended position designated by reference number
474, stop bracket 478 is inserted into the apertures designated by
reference number 480. In this configuration, stop bracket 478 not
only limits maximum displacement of spreader 400 with respect to
bridge 414, but also maintains end section 472 and 474 locked in
the extended position.
It will be readily apparent to those skilled in the art that the
material spreader system disclosed above may be modified in
numerous ways and may assume many embodiments other than the
preferred forms specifically set out and described above. For
example, bridge means 414 could include a third, centrally located,
slightly elevated third guide rail for the purpose of supporting a
second single roller truck. In this configuration, roller assembly
436 would include only three wheels but would operate in
substantially the same manner as that described above. In addition,
bridge means 414 could take the form of a vertically oriented
I-beam and the roller assembly coupled to spreader 400 could
include a plurality of spaced apart trucks which contact the side
surfaces of the I-beam as well as the upper surface of the lower
section of the I-beam. In this I-beam bridge configuration, the
vertical spacing between the wheels of the roller assembly would
prevent side to side swaying movement of spreader 400 while the
weight of spreader 400 would be supported by the lowermost wheels
of the roller assembly which would contact the lower, horizontally
oriented surface of the I-beam. Numerous other modifications would
be readily apparent to one skilled in the art. Accordingly, it is
intended by the appended claims to cover all such modifications of
the invention which fall within the broad scope of the material
spreader invention disclosed above.
* * * * *